System and a method for polishing optical connectors

ABSTRACT

A polishing system for polishing optical connectors includes at least one polishing station having a region of polishing film overlying a substrate block, and a polishing fixture ( 200 ). The polishing fixture has connector mounting holes ( 204 ) for receiving optical connectors and a working liquid supply arrangement including working liquid release channels ( 210 ) for directing working liquid to regions adjacent to the connector mounting holes. One or more of the working liquid release channels is inter-spaced between the connector mounting holes. The polishing system also includes a drive system ( 174 ) ( 176 ) ( 178 ) for generating relative motion between the polishing fixture and the polishing station so as to polish the optical connectors.

FIELD OF THE INVENTION

The present invention relates to the field of polishing connectors. Moreparticularly the present invention relates to a method for polishingoptical connectors and a system for implementing the method.

BACKGROUND OF THE INVENTION

With the growth of optical communication networks there is a growingneed for altering the network configuration, connecting to it new nodesand devices, disconnecting old devices and maintaining the network.These connections are easy and convenient to make with the help of anoptical connector, which is a demountable device for attaching anoptical fiber to another optical fiber, or to an active or passivedevice.

The losses of the optical signal power at each connection depend on thegeometry of the connector end-face, matching surfaces geometry, surfacequality and other parameters. In order to reduce optical signal powercoupling losses the end-face of an optical connector typicallycomprising an optical fiber inserted into a ferrule is polished. Thepolished end-face surface may be flat, inclined or have a radius inaccordance with the type of connection desired. The term “opticalconnector” as used herein in the description and claims denotes anypolished end-face region of a fiber configured for optical connection toan adjacent element. Typically, the optical connector includes a fiberend inserted into a ferrule, although optical connectors without aferrule (for example, certain MT type connectors) can also be polishedusing the systems and methods of the present invention.

Polishing of an optical connector on a piece-by-piece basis is notpractical due to the nature of the process as well as the mix of thequantities and the structure of the connectors to be polished. This isthe main reason why optical connectors are typically polished inbatches. For polishing, a batch of optical connectors is mounted in aso-called polishing fixture. U.S. Pat. No. 5,961,374 to Minami et al.discloses some such polishing fixtures. FIGS. 1A-1C illustrate someprior art polishing fixtures that may have round, polygonal, or anyother form. In these polishing fixtures the connectors, marked bynumeral 80, are mounted or attached to the periphery of a polishingfixture 82. Upon completion of the polishing operation, the connectorsare removed from the polishing fixture and a new batch of connectorsmounted. Mounting of the connectors along the periphery of the polishingfixture to some extent limits the number of connectors that may besimultaneously polished and the size of the polishing fixture.

U.S. Pat. Nos. 5,947,797, 6,183,343, and 6,190,239 all to Buzzettidisclose a polishing fixture (FIG. 1 d) where the connectors orsimilarly configured industrial components to be polished are mountedacross the fixture on a grid. This allows for simultaneous polishing ofa relatively large number of optical connectors.

Polishing is usually conducted in the presence of a working liquid,which may be water, a specially formulated water-based solution, or anyother fluid composition with suitable coolant and/or lubricantproperties. For the purpose of brevity, the description of the inventionbelow will refer to the working liquid by way of a preferred example as“water”. Nevertheless, it should be appreciated that all other workingliquids fall equally within the scope of the invention as claimed. Waterplays an important role in the polishing process. Water cools the partbeing polished, removes particles, contamination and other debris thatmay destroy a polished connector end-face made up of the fiber andferrule surface. The supply rate of water is controlled to maintainproper concentration of polishing slurry, and the water provideslubrication between polished parts and polishing substrate. Water (andsometimes other fluids) is usually delivered to the polishing member andto the actual polishing area, typically to the periphery of thepolishing fixture by a fluid delivery system separate from the polishingfixture. The central and other parts of the polishing area do not get asufficient amount of water. There is no method known to the inventors ofthe present invention of polishing a fiber and ferrule end-face on arotating, linearly moving, or static polishing member that ensuresproper water delivery to each and every polished connector mounted onthe polishing fixture.

There is no polishing fixture known to the inventors of the presentinvention capable of delivering the proper amount of water to eachconnector or each part of a plurality of parts being simultaneouslypolished.

In the context of present invention, “polishing member” means a parthaving a surface with polishing slurry, or having a rigid or a resilientsurface covered by polishing film or paper, on which actual polishingtakes place. The terms “polishing film”, “polishing paper”, and“polishing member” in the context of the present invention are usedinterchangeably unless specified otherwise.

When separate optical patch cords are polished the excessive fiberlength is mounted on a hanger, which in many instances is part of apolishing fixture. Recently the use of flexible optical circuits, whichrepresent multiple fiber bundles and cables proper routed and laminatedbetween two polymeric substrates, has increased. Polishing of theconnectors, which are terminations of the optical fiber cables andbundles forming the flexible optical circuit, is a complicate task,since it requires support of the complete flexible optical circuit. Thesupport of the flexible optical circuit should substantially eliminaterelative movement between the polished connector and the flexibleoptical circuit. There is no commercially available solution forpolishing of such flexible optical circuits.

Polishing film is an expensive material and its condition is importantfor proper polishing process. Rotating polishing members typically useonly a small part of the polishing surface or film. Methods ofoptimizing use of polishing surface or film placed on such a rotatingpolishing support are disclosed in U.S. Pat. No. 5,961,374 to Minami etal. Despite the various attempts described therein to optimize usage ofthe polishing materials, Minami et al. fails to address the fundamentaldrawback that polishing of the parts mounted on the polishing fixturetakes place at differing speeds. Specifically, since the different partsare mounted at different distances or radiuses of the polishing disk,the rotating polishing action results in unequal polishing conditionsand non-uniform wear of the polishing material.

U.S. Pat. Nos. 5,947,797; 6,183,343; 6,190,239; 6,302,763, and 6,428,391all to Buzzetti teach polishing on a linearly moving polishing member.Movement of the stages holding the polishing material or member ensuresa more uniform polishing material usage and equal polishing speed ofeach of the polished parts. Buzzetti's patents do not, however, teachoptimization of polishing material usage.

In both cases of a rotating or linearly moving polishing member,polishing film or paper exchange requires stopping the machine, removalof the previously used film, insertion of a new film, and restarting themachine for the next polishing cycle. This procedure results inconsiderable time wastage during the polishing process.

Polishing machines that use polishing film in the form of a web form areknown in the art. These machines allow polishing film exchange byautomatic polishing film advance, thereby saving time, as compared withmachines using film sheets placed over rotating or linearly movingpolishing film supports. In most cases, however, machines with automatedadvancing of polishing film tend to be inefficient in their use of thefilm. Loading and tensioning of polishing material on such machines iscomplicate and usually is performed by a number of rollers holding thepolishing material and, in some cases, rotating or moving together withthe polishing material.

The polished optical connector end-face surface may be flat or have aradius in accordance with the type of connector polishing desired. Flatfiber and ferrule end-faces are obtained by polishing on a flat rigidpolishing surface or member. Polishing on a polishing member havingresilient polishing surface results in a fiber and ferrule end-facehaving a curvature. There is no method known to the inventors of thepresent invention for polishing a fiber and ferrule end-face on astatic, non-moving polishing member that results in a fiber and ferruleend-face having a curvature.

Polishing of optical connectors and some other photonic elements may beperformed using a fixed set of polishing process parameters or inaccordance with a predefined set of polishing process parameterssometimes called a recipe. Development of recipes requires collection ofthe results of a large number of polishing cycles and statisticalprocessing of the results collected. This complicates instant correctionof the polishing process that may be required from one to the nextpolishing cycle. It would be desirable to have a system that has certainlearning features enabling adaptation of polishing process parameterssuch as polishing speed, polishing time, and place on the polishingmember selected in accordance with the results of the previous polishingcycle.

It would be also desirable to have an automated polishing systemsincorporating in it the discussed features and providing a fullyautomated Photonic components set-up, polishing, cleaning and inspectioncycle.

SUMMARY OF THE INVENTION

The present invention is a polishing system for polishing opticalconnectors.

According to the teachings of the present invention there is provided, apolishing system for polishing optical connectors, the polishing systemcomprising: (a) at least one polishing station including a region ofpolishing film overlying a substrate block; (b) a polishing fixturehaving: (i) a plurality of connector mounting holes disposed across anarea of the polishing fixture, each of the connector mounting holesreceiving an optical connector, and (ii) a working liquid supplyarrangement including a plurality of working liquid release channels fordirecting working liquid to regions adjacent to the connector mountingholes, at least one of the working liquid release channels beinginterspaced between a plurality of the connector mounting holes; and (c)a drive system for generating relative motion between the polishingfixture and the at least one polishing station so as to polish theoptical connectors.

According to a further feature of the present invention, each of theconnector mounting holes has a nearest neighbor spacing measured fromthe connector mounting hole to a nearest neighboring connector mountinghole, and wherein a spacing from each of a majority of the connectormounting holes to a nearest one of the working liquid supply channels isnot more than twice an average of the nearest neighbor spacings.

According to a further feature of the present invention, a majority ofthe connector mounting holes are substantially equidistant from anearest one of the working liquid supply channels.

According to a further feature of the present invention, the polishingfixture includes a mounting plate, both the connector mounting holes andthe working liquid supply channels being formed as openings through themounting plate.

According to a further feature of the present invention, the drivesystem is associated with the polishing fixture so as to move thepolishing fixture along a two-dimensional polishing path relative to theat least one polishing station and wherein the at least one polishingstation is configured to hold the region of polishing film static whilethe polishing fixture moves along the polishing path.

According to a further feature of the present invention, the drivesystem is further configured to raise the polishing fixture out ofcontact with the at least one polishing station on completion of apolishing operation.

According to a further feature of the present invention, the drivesystem is implemented as a set of three linear actuators.

According to a further feature of the present invention, there is alsoprovided an optical cable support including at least one reel forreceiving lengths of optical cables associated with the opticalconnectors being polished.

According to a further feature of the present invention, the cablesupport further includes a displacement mechanism configured to allowdisplacement of the reel in at least one direction.

According to a further feature of the present invention, a flexibleoptical circuit support rack associated with the polishing fixture forsupporting a flexible optical circuit associated with the opticalconnectors being polished.

According to a further feature of the present invention, the flexibleoptical circuit support rack includes a clamping plate extendingvertically above the polishing fixture, the clamping plate having a twodimensional array of bolt holes.

According to a further feature of the present invention, there is alsoprovided a cleaning station including: (a) a wiping cloth supply roll;(b) a wiping cloth receiving roll; (c) a length of wiping clothpartially stored on the supply roll and stretched to the receiving rollto as to leave an exposed wiping cloth region; and (d) a windingactuator associated with the receiving roll and configured for actuatingthe receiving roll so as to bring a new portion of the length of wipingcloth into the exposed wiping cloth region.

According to a further feature of the present invention, the supplyroll, the receiving roll and the length of wiping cloth are implementedas parts of a wiping cloth cassette.

According to a further feature of the present invention, there is alsoprovided: (a) a polishing film feed mechanism for selectively exchangingthe region of polishing film overlying the substrate block; and (b) acomputerized controller for controlling the drive system and the feedmechanism, the controller being configured to: (i) actuate the drivesystem during a first polishing operation so as to move a batch ofoptical connectors in a polishing motion along a corresponding set ofpolishing profiles in contact with the static polishing film, (ii)actuate the drive system during at least one additional polishingoperation so as to move a batch of optical connectors in a polishingmotion along a corresponding set of polishing profiles in contact withthe static polishing film, the polishing profiles of the additionalpolishing operation being interspaced with, and non-overlapping, thepolishing profiles of the first polishing operation, and (iii) actuatethe feed mechanism so as to advance the polishing film.

There is also provided, according to the teachings of the presentinvention, a polishing system for polishing optical connectors, thepolishing system comprising: (a) at least one polishing stationincluding a region of polishing film overlying a substrate block; (b) apolishing film feed mechanism for selectively exchanging the region ofpolishing film overlying the substrate block; (c) a polishing fixturehaving a plurality of connector mounting holes disposed across an areaof the polishing fixture, each of the connector mounting holes receivingan optical connector; (d) a drive system for generating relative motionbetween the polishing fixture and the at least one polishing station soas to polish the optical connectors; and (e) a computerized controllerfor controlling the drive system and the feed mechanism, the controllerbeing configured to: (i) actuate the drive system during a firstpolishing operation so as to move a batch of optical connectors in apolishing motion along a corresponding set of polishing profiles incontact with the static polishing film, (ii) actuate the drive systemduring at least one additional polishing operation so as to move a batchof optical connectors in a polishing motion along a corresponding set ofpolishing profiles in contact with the static polishing film, thepolishing profiles of the additional polishing operation beinginterspaced with, and non-overlapping, the polishing profiles of thefirst polishing operation, and (iii) actuate the feed mechanism so as toadvance the polishing film.

There is also provided, according to the teachings of the presentinvention, a polishing system for polishing optical connectors, thepolishing system comprising a cleaning station having: (a) wiping clothcassette including: (i) a wiping cloth supply roll, (ii) a wiping clothreceiving roll, and (iii) a length of wiping cloth partially stored onthe supply roll and stretched to the receiving roll to as to leave anexposed wiping cloth region; and (b) a winding actuator associated withthe receiving roll and configured for actuating the receiving roll so asto bring a new portion of the length of wiping cloth into the exposedwiping cloth region.

There is also provided, according to the teachings of the presentinvention, a method for polishing optical connectors of a flexibleoptical circuit, the method comprising: (a) providing a polishingfixture including: (i) a plurality of connector mounting holes disposedacross an area of the polishing fixture, each of the connector mountingholes receiving an optical connector, and (ii) a support rack forsupporting a flexible optical circuit; (b) mounting a flexible opticalcircuit with a plurality of optical connectors mounted in the connectormounting holes and with at least part of a body of the flexible opticalcircuit attached to the support rack; and (c) generating relative motionbetween the polishing fixture and a polishing surface.

According to a further feature of the present invention, the relativemotion is generated by a drive system associated with the polishingsystem, the polishing surface remaining static at least during a givenpolishing operation.

There is also provided, according to the teachings of the presentinvention, a method of polishing of the leading end face portion of aplurality of batches of optical connectors having a foremost end havinga ferrule integrated with optical fiber, comprising steps of: (a)mounting first batch of optical connectors in a polishing fixture havinga plurality of optical connectors mounting holes at a predeterminedinclination angle and a plurality of working liquid delivery openingsinterspaced with the optical connectors mounting holes; (b) bringing theleading end faces of the mounted in the polishing fixture first batchoptical connectors into forced contact with a static polishing member;(c) sliding the polishing fixture with the first batch of opticalconnectors simultaneously in two independent and orthogonal directionson the polishing member; (d) supplying through a plurality of openingsand channels in the polishing fixture a working liquid to a plurality ofoptical connectors being polished and to the polishing member; (e)polishing the surface of the leading end face portion of the first batchof optical connectors by the sliding movement in a brushing patterngenerated by independent changes of the sliding movement speed in eachof the two orthogonal polishing fixture movement directions; and (f)controlling all of the polishing and auxiliary processes by a computer,the computer monitoring and memorizing all of the processes steps andparameters, wherein at least one of the polishing process parameters forpolishing the surface of the leading end face portion of at least one ofthe following optical connector batches is changed by the computer,based on the results of previously polished optical connectors batch.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of non-limiting example only,with reference to the accompanying drawings, wherein:

FIGS. 1A-1D are schematic illustrations of prior art polishing fixtures;

FIG. 2 is a general block scheme of the optical connectors polishingsystem of the present invention;

FIG. 3 is a schematic top view illustration of the polishing station ofthe present invention;

FIG. 4 is a top view illustration of an exemplary embodiment of apolishing fixture of the present invention;

FIGS. 5A and 5B are cross-sections of an exemplary embodiment of apolishing fixture of FIG. 4, which is part of the present invention;

FIG. 6 is a three dimensional representation of polishing fixture ofFIG. 4 coupled with a bayonet type lock and a unit allowing its rigid orfloating position on the polishing surface;

FIGS. 7A and 7B are schematic illustrations of exemplary shapes offlexible printed circuit boards with optical fiber bundles and opticalconnectors;

FIGS. 8A and 8B are respectively front and rear view of an exemplarypolishing fixture of the present invention for polishing of flexibleoptical circuit boards with optical fiber bundles and opticalconnectors;

FIGS. 9A and 9B are schematic illustrations of the polishing fixture ofFIG. 8 the present invention for polishing of flexible printed circuitboards with mounted on it flexible printed circuit boards with opticalfiber bundles and optical connectors;

FIG. 10 illustrates a polishing fixture for polishing of non-standardfiber length cable;

FIG. 11 is an illustration of an exemplary embodiment of a polishingsub-system of the present invention;

FIG. 12 is an illustration of an exemplary embodiment of a polishingunit of the present invention;

FIG. 13 is an illustration of an exemplary embodiment of a polishingfilm supply roll of the present invention;

FIG. 14 is an illustration of operating principles of an exemplaryembodiment of a polishing film supply cassette unit of the presentinvention;

FIG. 15 is a schematic illustration of another exemplary embodiment of apolishing film supply and receiving cassette unit of the presentinvention;

FIG. 16 is a schematic three dimensional view of the of the polishingsub-system of the polishing station of the present invention equippedwith polishing film supply and receiving cassette unit;

FIG. 17 is a schematic three dimensional view of the of the wiping clothsupply and receiving cassette unit of an exemplary embodiment of thepresent invention;

FIG. 18 is an illustration of a sliding movement pattern of thepolishing fixture of an exemplary embodiment of the present inventionand the resulting optical connector polishing trajectory;

FIG. 19 is an illustration of a method of economic use of polishingmember by selection of different polishing areas, which is part of thepresent invention; and

FIG. 20 is a schematic illustration of polishing speed vectors ofdifferent parts of polishing fixture.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The principles and execution of a method according to the presentinvention, and the operation and properties of a polishing systemdescribed thereby may be understood with reference to the drawings andthe accompanying description of non-limiting, exemplary embodiments.

By way of general introduction, before addressing the drawings indetail, it should be appreciated that certain preferred implementationsof the present invention provide a polishing system comprising a set-upstation for proper position and mounting of a plurality of opticalconnectors to be polished and a polishing station. The polishing stationoptionally and preferably may include in addition to a polishingsub-system, a cleaning sub-system, a rinsing and drying sub-system, aninspection subsystem, and a control computer controlling the operationof all sub-systems and stations comprising the polishing system.

In accordance with one exemplary embodiment of the present invention theobject of providing a method of polishing optical connectors or otherphotonic elements in which each of the optical connectors or otherphotonic elements being polished gets equal and sufficient amount ofwater may be achieved by providing an optical connector polishing systemfor polishing optical connectors including a polishing fixture having aplurality of optical connectors mounting holes. The optical connectorsmounting holes optionally and preferably are distributed across the areaof the polishing fixture and not only along the perimeter of thepolishing fixture. Mounting a plurality of optical connectors to bepolished in the mounting holes of the polishing fixture, polishing theplurality of connectors mounted in the mounting holes of the polishingfixture and delivering water to each of the plurality of opticalconnectors being polished through the water delivery openings placed inthe spaces between said plurality of optical connectors mounting holes.

In accordance with another exemplary embodiment of the present inventionthe object of providing a method of simultaneous polishing of a largenumber of optical connectors and other photonic elements in which thepolishing speed of each optical connector and other photonic elements isequal may be achieved by mounting a plurality of optical connectors in apolishing fixture and polishing them on a flat static polishing member.The polishing fixture may optionally and preferably have a plurality ofoptical connectors mounting holes distributed across the surface of thepolishing fixture and not only along the perimeter of the polishingfixture. Optionally but not necessary the mounting holes of thepolishing fixture may be located on a grid.

The leading portion of an optical connector end-face may be polished toa flat surface by polishing it on a rigid flat static surface, Inaccordance with yet another exemplary embodiment of the presentinvention the leading portion of the optical connector end-face may bepolished into a curved surface by said sliding movement in at least twoorthogonal directions. The polishing member in this case is optionallyand preferably a resilient, web-polishing member. The resilientweb-polishing member is static in process of polishing.

A polishing fixture sliding mechanism capable of sliding said polishingfixture simultaneously in at least two orthogonal directions on thestatic polishing member provides all required for polishing fixturemovements. The sliding mechanism optionally and preferably slides thepolishing fixture simultaneously in at least two orthogonal directionsand the sliding speed in the first direction is independent andoptionally and preferably different of the sliding speed in the seconddirection, and the sliding movement of the polishing fixture is a sum ofthe first and second independent movements. The polishing fixturesliding mechanism is further capable of applying a controlled force tosaid polishing fixture and measuring the advance or descent speed of thepolishing fixture.

Economic polishing film usage in accordance with the present inventionis achieved by positioning the polishing fixture holding a plurality ofoptical connectors to be polished on a first section of a staticpolishing member. Polishing the first plurality of optical connectors byoperating said polishing fixture sliding mechanism capable of slidingsaid polishing fixture simultaneously in at least two orthogonaldirections on the first section of static polishing member. Positioningthe polishing fixture holding the next plurality of to be polishedoptical connectors on a second section of a static polishing member,where the second section is different from the first section andoptionally and preferably does not overlap the first section. Polishingthe second plurality of optical connectors by operating said polishingfixture sliding mechanism capable of sliding said polishing fixturesimultaneously in at least two orthogonal directions on the secondsection of static polishing member.

In accordance with an additional exemplary embodiment of the presentinvention, a control computer controls the process of positioning thepolishing fixture on the first section of the static polishing memberand optionally and preferably records the coordinates of the firstsection or polishing area. The control computer calculates thecoordinates of the second section or polishing area of the staticpolishing member and optionally and preferably positions on it thepolishing fixture for the next polishing cycle. Control computer takescare that the second polishing area preferably does not overlap with thefirst polishing area. The polishing fixture sliding mechanism performsboth the operational or polishing movement holding the polishing fixturewith a plurality of optical connectors over the first section of thepolishing member and the auxiliary movement of repositioning thepolishing fixture next plurality of to be polished to the second sectionof a static polishing member.

The present invention provides a method of easy web polishing materialexchange that does not require any special operator skills and maintainsthe same polishing film tension and adhesion to the underlying polishingmember surface. In accordance with this method, the polishing film isprovided in a polishing film supply cassette for supply and tensioningthe polishing film.

According to one of the embodiments, the polishing film supply andtensioning cassette or roll is preferably a disposable cassette andcomprises a hollow cylindrical core having first and second end with thepolishing film wind on the hollow cylindrical core. The hollowcylindrical core with the film rotates on a shaft. Friction between thehollow cylindrical core and a pair of expandable cylindrical insertsholds the hollow cylindrical core on the shaft. The expandablecylindrical inserts change the force, and accordingly the torque, theyapply to the hollow cylindrical core as a function of the pressureapplied to them by outer tapered cylinders inserted at both ends of thehollow core and inner tapered cylinders. A flexible element, such as aspring inserted between the inner tapered cylinders generates thepressure. Both outer and inner tapered cylinders are movably coupledwith a common shaft. One of external tapered cylinders is rigidlycoupled with the shaft. Second external tapered cylinder can slide onthe shaft, although it can be fixed in any sliding position and becomerigidly coupled with the shaft. Inner tapered cylinders can slide onshaft, but preferably rotate with it. The tension of unwind film isregulated by the force required to overcome the pressure generated bythe flexible element.

According to the present invention, the polishing film dispensed fromthe supply roll or cassette is tensioned and adhered to a polishingunit, comprising a rigid frame having a flat surface, and an elastic orrigid member, placed in a trough in the flat surface. The polishing filmis supplied by a polishing film supply roll or cassette and is disposedon the elastic or rigid member surface of the polishing unit. Thereceiving cassette or roll is capable of incrementally unwinding andadvancing the polishing film. Polishing film is advanced between thepolishing cycles and remains static in the course of the polishingprocess. Water ensures polishing film adhesion to the resilient or rigidinsert of the polishing member. The force required to advance thepolishing film regulates polishing film tension and provides additionalpolishing film adhesion force. The force is a function of the pressuredeveloped by flexible element.

According to another exemplary embodiment, the polishing film cassetteis preferably a disposable cassette containing in a common package bothfilm supply roll and film receiving roll. The polishing film istensioned in the cassette and the force required to advance thepolishing film regulates polishing film tension. Exchange of thecassette causes simultaneous change of both film supply roll and filmreceiving roll.

According to yet another exemplary embodiment, the wiping cloth may bepackaged in a cassette, which is preferably a disposable cassettecontaining in a common package both wiping cloth supply roll and wipingcloth receiving roll. The wiping cloth is tensioned in the cassette andthe force required to advance the wiping cloth regulates wiping clothtension. Exchange of the cassette causes simultaneous change of bothwiping cloth supply roll and wiping cloth-receiving roll.

According to another exemplary embodiment of the present inventioncontrol computer optionally and preferably monitors and stores in thememory the polishing speed, polishing fixture descent speed, number ofpolishing cycles made on the same polishing area, amplitude, and speedof orbital or brushing movement, and results of polished partsinspection. Based on the previous polishing cycle parameters and resultscontrol computer calculates and provides at least one parameter for thenext polishing cycle. Such polishing process parameter may be polishingspeed, polishing time, force applied to the polishing fixture, place onthe polishing member and others.

The methods as described above provide advantages over the prior art inthat the polishing of the end faces of a plurality of optical connectorsis done in identical polishing conditions. Adequate water supply to eachpolished connector prevents polished surface degradation bycontamination due to polishing residuals, reduces potential of surfacescratches, and maintains constant the polished parts temperature. Amplesupply of water washes out polishing residuals and promotes fasterconditioning of the polishing film or polishing member. Freedom fromsuch contaminations and polishing residuals increases the yield ofoptical connectors polished according to the present invention.

In addition, the present invention offers another advantage in providingall movements required for proper polishing by only two simultaneoussliding movements of the polishing fixture. The resulting movement ofthe polishing fixture over the static polishing member is a sum of thesetwo independent sliding movements. By controlling the amplitude andphase of each of the independent movements, it is possible to generateany brushing or orbital movement trajectories of the polishing fixture.This makes the polishing sub-system architecture simple and thepolishing machine less expensive. There is no need for complicateeccentric mechanical arrangements or pulleys supporting a limited amountof orbital movements and requiring additional sources of rotational orlinear movement.

A further advantage of the present invention is that one polishingfixture sliding mechanism performs both the operational or polishingmovement of sliding the fixture over a polishing area and the auxiliarymovement of repositioning the polishing fixture over another section ofa static polishing member.

An additional advantage of the invention is that the polishing member orfilm is static in the course of the polishing process. This simplifiesthe polishing film to the polishing unit surface or insert surfaceadhesion. A polishing film supply cassette that keeps the polishing filmtension constant supplies the polishing film. A polishing film receivingcassette advances in case of need the polishing film in the intervalsbetween two polishing cycles. The loading of the polishing film supplycassette is simple and does not require special operator skills. Thepolishing film tension is constant throughout the polishing process andcontributes to the consistency of polishing results.

A further advantage provided by the method of the present invention isin the economic use of polishing material mounted on a static polishingmember. The economic use of the polishing material is achieved by thelay out of optical connectors in the polishing fixture and by makingeach next polishing cycle on a new section or area of the polishingmember not overlapping with the previously used section or area of thepolishing member. The control computer keeps track of polishing materialsections or areas used for polishing in previous polishing cycles andselects for the next polishing cycle new sections or areas of thepolishing member that do not overlap with the previously used polishingmember sections or areas.

The present invention also supports consistency of the polishing processby introducing corrections based on the results of the previouspolishing cycle in the next polishing cycle polishing parameters. Suchpolishing parameters may be polishing speed, polishing time and others,as may be required by the particular polishing process.

Turning now more specifically to the Figures, FIG. 2 is a general blockscheme of the optical connectors polishing system of the presentinvention. The integrated, automated optical connectors polishing system100 may include a polishing station 102 and a preparation station 104. Acontrol computer 106 governs operation of both polishing station 102 andpreparation station 104. Computer 106 may control all polishing systemprocesses and in addition to this such processes as inspection, performstatistical process analysis, keep process and parts databases, andissue different reports. Additionally, control computer 106 may containprograms enabling the learning of processes. The learning capabilitiessupport continuous polishing process improvement. They may identifyprocess degradation parameters and indicate on reasons causing theprocess degradation. Alternatively, each of the stations may have itsown dedicated computer. In this case, the distributed computers wouldcommunicate between them via a network.

Control computer 106 may control polishing station 102, preparationstation 104, and optional robotic arm 110. Computer 106 may control allinspection processes, perform statistical process analysis, keep processand parts databases, and issue different reports. Additionally, controlcomputer 106 may contain programs enabling process learning. Thelearning capabilities support continuous polishing process improvement.They may identify process degradation parameters, for example a worn-outabrasive, and may indicate reasons for said process degradation, whichrequire some on-line compensation, for example, adding more time to acertain step.

An operator stand 108 with monitor and Graphic User Interface (GUI)allows interactive operator intervention into each stage of the process.Control computer 106 uses a monitor with Graphic User Interface todisplay process status, and provide the operator with other usefulinformation and images of the work-pieces being processed. An optionalrobotic arm 110 for transfer of work pieces between preparation stationand polishing station may also be included into the automated opticalconnectors polishing system 100.

The following description provides detailed information on some of themain components of an integrated, automated optical connectors polishingsystem of the present invention.

FIG. 3 is a schematic top view illustration of polishing station 102 ofthe present invention. Polishing station 102 may include a main frame150 on which a flat and rigid plate 154 may be mounted. Optionallyattached to the top surface of plate 154 may be some sub-systemsincluded in polishing station 102. FIG. 3 shows a polishing sub-system152 containing a number of polishing units 156. A cleaning unit 158 forcleaning polished optical connectors of polishing process contaminationsmay also be positioned on the top part of plate 154. For the simplicityof explanation, plate 154 is shown cut away in a number of places, aswill be clear from the following description. A rinsing and drying unit162 and wiping unit 164 may be located on the top part of plate 154. Acut-away region of plate 154 renders visible polished connectorsinspection unit 166. Inspection unit 166 may optionally be positioned ina recess of the top plate 154 and may be attached to the bottom surfaceof plate 154.

Polishing fixture 200 with a plurality of optical connectors (not shown)is attached by means of bayonet type pins 250 (See FIG. 6) to a rigidmount 172. Rigid mount 172 optionally and preferably has freedom ofmovement in X, Y and Z directions. Digitally controlled linear actuators174, 176, and 178 provide respectively movement in X, Y, and Zdirections. Digital control facilitates independent movement in each ofthe X, Y, and Z movement directions. Linear actuators 174, 176, and 178can move and position polishing fixture 200 to virtually any pointlocated on the top part of plate 154 of polishing station 102. Linearactuators 174, 176, and 178 optionally and preferably provide bothoperational movements required for the polishing of optical connectors,and auxiliary movements required for positioning polishing fixture 200.When moving polishing fixture 200 from one sub-system to othersub-system, linear actuators 174, 176 and 178 function as a built-inrobotic system. The optional robotic arm 110 mentioned above, whenpresent, is typically only required for displacements outside the rangeof the polishing system, or for additional functions such as automatedset-up functions.

Some of the sub-systems of the polishing station and relevant to theinvention will be explained now in detail. FIG. 4 is a top viewillustration of an exemplary embodiment of a polishing fixture of thepresent invention. In accordance with this exemplary embodiment of thepresent invention the object of providing a method of polishing opticalconnectors in which all optical connectors being polished receive equaland sufficient amounts of water may for example be achieved by providinga polishing fixture 200. Polishing fixture 200 comprises a solid body202 having a plurality of optical connectors mounting holes 204. Opticalconnectors mounting holes 204 optionally and preferably are distributedacross the area of the polishing fixture, and not just along theperimeter of polishing fixture 200. As a preferred option, but not as arequirement, optical connectors mounting holes 204 of polishing fixture200 are located on a grid. Mounting of optical connectors in mountingholes 204 is typically achieved by using clips or inserts as is known inthe art. By way of one non-limiting example, a quick release insert,such as LC-12 Port Tablock, commercially available from DomailleEngineering LLC., Rochester, Minn. USA, (not shown) enables fast andeasy mounting of a plurality of optical connectors (not shown) to bepolished in mounting holes 204 of polishing fixture 200. Polishingfixture 200 has a plurality of water delivery openings 210 made in solidbody 202 of polishing fixture 200. Water delivery openings 210 arelocated in the spaces between optical connectors mounting holes 204 andthey terminate in conical flares 208 (FIG. 5B) guiding water to everyconnector being polished. Holes 212, 214 and 216 assist in the mountingof polishing fixture 200 to unit 252 (shown in FIG. 6) enabling floatingor rigid positioning and operation of polishing fixture 200. In thecourse of the polishing process, water is delivered to the polishingmember and to each connector to be polished simultaneously through eachactive water delivery openings 210. Where not all connector mountingholes are in use, the water supply is preferably only connected (oractivated) to selected water delivery openings 210 adjacent to themounting holes in use.

With regard to the spacing of water delivery channels or openings 210,it is a particularly preferred feature of one aspect of the presentinvention that the water delivery openings are interspaced betweenconnector mounting holes 204. Preferably, a spacing from most or all ofconnector mounting holes 204 to a nearest one of the water supplychannels 210 is not more than twice an average of the nearest neighborspacings of the mounting holes themselves. Most preferably, most or allof the connector mounting holes 204 are substantially equidistant fromthe nearest water supply channel 210. Water delivery holes 210 may berandomly spaced/positioned on the polishing fixture or arbitrarilypositioned according to any desired pattern, although the polishingresults in some instances may be inferior for unevenly spaced holescompared to a substantially evenly spaced arrangement of working liquiddelivery holes.

Parenthetically, it should be noted that, although described herein inthe context of a preferred embodiment in which a polishing fixture movesacross a static polishing station, the interspaced working fluiddelivery channel feature of the present invention is also applicable toother configurations such as where a circular fixture is brought intocontact with a rotating polishing disk.

FIG. 5A is a cross-section A-A of an exemplary embodiment of a polishingfixture of FIG. 4, which is part of the present invention. Cross-sectionshows that axis 220 of optical connectors mounting holes 204 has aninclination angle ALPHA. Use of an inclination angle for correctingmismatch between the apex of the curved polished optical connectorend-face and the optical axis of the curved surface is known in the art,and is not part of the invention. Inclination angle ALPHA may bedifferent for different types of optical connector. Consequently, foreach type of connector, a polishing fixture having a differentinclination angle may be required. Optionally quick release inserts (notshown) may be adjustable and change their angle to meet particularconnector polishing requirements.

FIG. 6 is an isometric representation of polishing fixture 200 coupledwith a bayonet type lock 250, and having a unit 252 which allows fixture200 to be positioned in rigid or floating relation to the polishingmember surface. Unit 252 allowing rigid or floating positioning ofpolishing fixture 200 on the polishing member surface is described indetail in a co-pending co-assigned patent application no. WO 03/023537and is not per se part of the present invention. Tubing 256 conductswater to water delivery openings 210. Receptacle (not shown) connectsunit 252 to pressurized air supply. The applied air pressure controlsthe floating or rigid operational mode of unit 252. A carry handle 260supports easy and convenient manual transportation of loaded by opticalconnectors polishing fixture 200 from preparation station 104 (FIG. 2)to polishing station 102. Optional robotic arm 108 uses bayonet lock 250for transportation of polishing fixture 200 between polishing systemstations. For the movements within the polishing station itself linearactuators 174, 176 and 178 optionally and preferably provide bothoperational movements required for the polishing of optical connectors,and auxiliary movements required for positioning polishing fixture 200.

Excess length of standard length fiber optics cables and patch cords islocated during the preparation and polishing process on a hanger 268.Hanger 268 has protruding ends 270 that prevent slippage of fiber opticsbundles in the course of the polishing process. This type of handling ofthe excess length of the fibers is suited for relatively short fiberssuch as standard 3 feet, 4 feet, and 6 feet length fiber optics cablesand patch cords. In an ever growing proportion of cases, opticalcircuitry with much longer non-standard fiber length cable and flexibleoptical circuitry are used, ranging from 30 feet up to thousands offeet. These cases present more complicated handling requirements. Anexample of a support arrangement for mounting devices of these typeswill now be described with reference to FIGS. 7A-9B.

FIGS. 7A and 7B are schematic illustrations of exemplary shapes offlexible printed circuit boards with optical fiber bundles and opticalconnectors, referred to as flexible optical circuit boards 400.Typically, the layout of such boards takes arbitrary shapes matching thelayout of the communication systems in which it will be placed. Numeral402 marks optical fiber bundles incorporated in flexible optical circuitboards 400, and numeral 406 marks optical connectors attached to opticalfiber bundles 402, although some of the bundles may be ended just bybare fibers and not by connectors. Body 412 of flexible optical circuitboard 400 has mounting holes 410 for mounting optical circuit board 400in its packaging.

Polishing of such optical connectors incorporated in a flexible opticalcircuit board is complicated since the board should be supported duringthe process and preferably there should be minimal relative motionbetween polished connector 406 and board 400. Relative motion betweenpolished connector 406 and flexible board 400 weakens the fiber toconnector connection point and may result in a broken fiber orintroduction of cracks into the fiber. Connectors coming out of flexibleboards are not necessary equally spaced, fiber cable or bundles may havedifferent lengths, and types of connectors connected to these fibercables may be different.

Use of a polishing fixture having a plurality of connectors mountingholes spread across the surface of the fixture enables easier connectorspositioning in the mounting holes than fixtures having the connectorsmounting holes distributed along the perimeter of the fixture. FIG. 8Aand FIG. 8B are respectively front and rear view of an exemplarypolishing fixture of the present invention for polishing flexibleprinted circuit boards with optical fiber bundles and opticalconnectors. A polygonal prismatic mounting structure 420 is rigidlyattached by means of four poles 424 to solid body 202 of polishingfixture 200. Polygonal prismatic mounting structure 420 has a pluralityof mounting holes 428 to which the body of flexible optical circuit ispreferably fastened for polishing purposes with the help of flexibleoptical circuit mounting holes 410.

Before the polishing process takes place, flexible optical circuitry 400is mounted on polygonal prismatic mounting structure 420 and fastened toit. Fiber optics connectors 406 are inserted in mounting holes 204 offixture 200.

FIG. 9A and FIG. 9B are schematic illustrations of another exemplarypolishing fixture of the present invention for polishing of flexibleoptical circuits with mounted on it flexible optical circuits withoptical fiber bundles and optical connectors. FIG. 9A illustrates thecase of mounting and polishing of two flexible optical circuits 400 andFIG. 9B shows the case of mounting and polishing of four flexibleoptical circuit 400. Other numerals mark like parts described in theprevious figures. Simultaneous polishing of both connectors that arepart of flexible optical circuitry and fiber optic patch cords ispossible.

FIG. 10 illustrates a polishing fixture for polishing ends ofnon-standard length fiber cable. Non-standard length fiber cables aretypically mounted on reels, such as reels 430. Each reel may containcables with length of 2000 meters or more. For polishing purposes, eachreal 430 is mounted on a reel rack 432, cable to be polished is clampedby clamp 434, and cable connector is fixed in a regular way in polishingfixture 200. Reel rack 432 is attached to guides 174 and moves with itin at least one direction during the polishing, thereby minimizing thelength of the loop of free optical cable. The motion of the reels may befree, by linkage to part of the linear actuator system, or underoperation of an independently actuable drive system. Reels 430containing different length optical cables may be polishedsimultaneously.

FIG. 11 is an illustration of an exemplary embodiment of a polishingsub-system of the present invention. Polishing sub-system 152 includes arigid frame 280 on which optionally, and preferably, a number ofindependent polishing units 156 are located. An individualpolishing-film supply roll 282 (or optionally a cassette as will bedescribed below) supplies polishing-film 286 to each polishing unit 156.Polishing-film receiving roll 284 or cassette advances a predefinedlength as required during the intervals between polishing cycles.Polishing-film receiving roll 284 also collects used polishing-film 286.Each polishing-film receiving roll 284 has an independent drive 294(only one is shown). Polishing-film 286 is tensioned and adhered to topsurface 288 of each polishing unit 156. Each polishing roll 282 maycontain different type of polishing-film 286, and each polishing-filmmay be loaded with a different film tension.

Top surface 288 of each polishing unit 156 has a set of rulers 290forming a trough in which, in accordance with the polishing processdesired, a resilient material, such as rubber insert 292 or a rigidmaterial insert 296, such as for example a glass or aluminum insert orpad may optionally be placed. When the end-face of optical connector hasto be polished to a spherical shape, a rubber insert 292 or an insert ofother suitable resilient material such as polyurethane is placed in thetrough. In case where the end-face of optical connector has to bepolished to flat shape a rigid insert 296 is placed in the trough.

A cross section of an exemplary embodiment of a polishing unit 156 ofthe present invention is shown in FIG. 12. Polishing unit 156 consistsof a solid body 304 with top surface 288. Top surface 288 has a set ofrulers 290 (FIG. 11) forming a trough in which, in accordance with thepolishing process desired, a resilient material such as rubber insert orpad 292 or a rigid material insert 296 (not shown) is placed. Polishingfilm supply cassette 282 supplies polishing film 286. As polishing filmis dispensed under tension by polishing film supply cassette 282 itpasses over a bar 306. Bar 306 has a semi-round shape, and a hole 308extends through the whole length of bar 306. The semi-round shape of bar306 serves as a polishing-film guiding radius, which prevents the bottomsurface of polishing-film 286 from damage when it is advanced by pullingit from cassette 282. In addition to this, water is supplied throughhole 308 extending through the whole length of bar 306 to the lowersurface of polishing film 286. Water exits bar 306 through a series ofsmall holes 352 (FIG. 14) that on one side are in fluid communicationwith water supplying hole 308 and on the other side are in contact withthe bottom surface of polishing film 286. Water wets the bottom surfaceof polishing film 286 as it is advanced and enhances its adhesion withrubber pad 292 or rigid insert 296 (not shown). When all polishing film286 contained in polishing cassette 282 is used, cassette 282, which isoptionally and preferably a disposable cassette is easy pulled out andreplaced by a new cassette.

Polishing-film receiving cassette or roll 284 (FIG. 11) collects usedand advanced polishing-film 286. Used polishing film is wound on shaft314. A motor 294 through a gear 318, only part of which is shown,rotates shaft 314 and pulls polishing film 286 out of cassette 282. Whenpolishing-film receiving cassette or roll 284 (FIG. 11) is full, it isejected by ejection handle 322. Adjustable mounts 324 serve for mountingand leveling of polishing unit 156 on the rigid frame 280 of polishingsub-system 152.

Operation of an exemplary embodiment of polishing film dispensing orsupply cassette 282 will be explained in detail now. In accordance withthe present invention, polishing-film supply cassette 282, illustratedin FIG. 13, is optionally and more preferably a disposable polishingfilm supply cassette. Polishing-film supply cassette 282 provides amethod of easy web polishing material exchange that does not require anyspecial operator skills, and maintains the same polishing film tensionand adhesion to the underlying polishing member surface.

Polishing-film supply roll or cassette 282 comprises a hollowcylindrical core 330, having first 332 and second 334 end with polishingfilm 286 (shown here cut away) wound on hollow cylindrical core 330.Friction between hollow cylindrical core 330 and expandable cylindricalinserts 338 and 340 holds hollow cylindrical core 330 on a shaft 336.External tapered cylinders 344 and 346 inserted at both ends of thehollow core press expandable cylindrical inserts 338 and 340 againstinner tapered cylinders 348 and 350. One of external tapered cylindersfor example 346 is rigidly coupled with shaft 336. Second externaltapered cylinder for example 344 can slide on shaft 336, although it canbe fixed in any sliding position and become rigidly coupled with shaft336. Inner tapered cylinders 348 and 350 can slide on shaft 336. Aflexible element, such as a spring 354 applies counter pressuretensioning inner tapered cylinders against outer tapered cylinders.

FIG. 14 is an illustration of operating principles of an exemplaryembodiment of a polishing film supply roll or cassette unit of thepresent invention. Polishing film 286 is supplied as a roll deployedaround a hollow cylinder 330 (shown here cut-away to reveal the internalelements of the supply roll). Within hollow cylinder 330 are a pair oftapered cylinders 348 and 350 which are biased outwards by a spring 354so as to tend to expand a corresponding pair of expandable cylindricalinserts 338 and 340, thereby generating friction braking force on theinside surface of hollow cylinder 330. A stopper pin 356 engages with anotch in solid body of polishing unit 304 and prevents rotation of shaft336, and hence also of expandable cylindrical inserts 338 and 440. Thetension of unwind polishing-film is thus regulated by the forcenecessary to overcome the braking torque created by expandablecylindrical inserts 338 and 440 bearing outwards on hollow cylinder 330.

Polishing-film supply roll or cassette 282 is optionally and preferablya disposable cassette. Cassette manufacturer regulates the preloadgenerated by flexible element 354. This ensures a constant and equalvalue for each cassette and accordingly constant and repeatable filmtension values.

In another exemplary embodiment of the present invention shown in FIG.15 and FIG. 16, polishing-film supply and collecting cassette isoptionally and preferably a disposable cassette comprising mounted in asingle body 362 polishing-film supply roll 282 and polishingfilm-receiving roll 314. The tension of polishing film 286 is set duringthe cassette assembly process and it is regulated by the force necessaryto overcome the torque created by the force applied by flexible element354 (FIGS. 13 and 14) to inner tapered cylinders 348 and 350. Cassettebody 362 snaps into its position on each polishing unit 156. Polishingfilm-receiving roll 314 engages through gear motor 294 that enablespolishing film movement and exchange.

In yet another exemplary embodiment of the present invention shown inFIG. 17, a wiping cloth and collecting cassette is optionally andpreferably a disposable cassette comprising mounted in a single body 368wiping cloth 370 supply roll and wiping cloth receiving roll. Thetension of wiping cloth 370 is set during the cassette assembly processand it is regulated similarly to the polishing film regulation tension.Cassette body 368 snaps into its position on a polishing unit 156 or astructure similar thereto. No water is supplied through the wipingprocess.

Polishing fixture-sliding mechanism includes X and Y-axis drives 174 and176 (FIG. 3), respectively, and control computer 106 (FIG. 2). Thesliding mechanism optionally, and preferably, slides the polishingfixture simultaneously in at least two orthogonal directions and thesliding speed in the first direction is independent and different of thesliding speed in the second direction, and the sliding movement of thepolishing fixture is a sum of the first and second independentmovements. Control computer 106 generates the type of movement desiredand through digital control means controls the speed of the independentmovement of each linear drives 174 and 176. Digital control meansdriving X and Y linear drives 174 and 176, with suitable signals, mayachieve in addition to polishing movement an orbital or brushingmovement of polishing fixture 200 (FIG. 4 and FIG. 6). For example,driving one of the linear drives with a signal of form K sin(ω) and theother with a signal of form K cos(ω), where both signal have an equalfrequency and amplitude, will result in circular orbital movement shownin FIG. 18 by line 380. Changing the amplitude of one of the drivesignals will result in an elliptical orbital movement. Other orbitalmovement patterns, such as the figure eight, shown by line 382 andothers may be achieved by changing the drive signals shape, frequency,and amplitude. The polishing fixture sliding mechanism is furthercapable of applying force to polishing fixture 200 schematically shownby bayonet type lock 250, and unit 252 allowing its rigid or floatingposition on polishing member (film) surface 286 and measuring polishingfixture descent speed. Numerals 282 and 286 indicate polishing filmsupply cassette and polishing film receiving cassette respectively.

FIG. 19 is an illustration of an economical method for use of apolishing member by selection of different polishing sections or areason polishing member. Economic polishing-film usage in accordance withthe present invention is achieved by: (a) positioning polishing fixture200 holding a plurality of optical connectors to be polished on a firstpolishing section or area 384 defined by the boundaries of polishingfixture 200 on a static polishing film (member) 286; (b) operating saidpolishing fixture sliding mechanism capable of sliding said polishingfixture simultaneously in at least two orthogonal directions on thestatic polishing member 286 for polishing said first plurality ofoptical connectors; (c) positioning next polishing fixture 200′ holdingthe next plurality of to be polished optical connectors on a secondpolishing section or area 386 defined by the boundaries of repositionedpolishing fixture 200′ on a static polishing film (member) 286, wherethe second polishing area 366 is different from the first polishing area384 and does not overlap with first polishing area; and (d) operatingsaid polishing fixture sliding mechanism capable of sliding saidpolishing fixture simultaneously in at least two orthogonal directionson the second polishing section or area of the static polishing memberfor polishing said second plurality of optical connectors.

In accordance with an additional exemplary embodiment of the presentinvention, control computer 106 (FIG. 2) optionally and preferablycontrols the process of positioning polishing fixture 200 on firstpolishing area 384 on static polishing member 286 and optionally andpreferably records the parameters (coordinates) of first polishing area384. Control computer 106 calculates coordinates of second polishingarea 386 on static polishing members 286 and optionally and preferablypositions on it polishing fixture 200 for the next polishing cycle.Control computer 106 takes care that second polishing area 386preferably does not overlap with first polishing area 384.

Digitally generated and controlled orbital movement combined with astatic polishing member provides a number of options and benefits thatexisting conventional rotating disk polishing mechanical systems do notsupport. Change of orbital polishing pattern movement is one of them inaddition to this variable speed within the same orbital movement patternis possible. The flexibility of movement patterns combined with betterspeed control provides a higher polished surface quality.

Digital control of the speed of orbital movement pattern facilitatesbetter polishing speed control. The parallel motion is alsoadvantageous, equalizing the polishing speed of different opticalconnectors mounted on polishing fixture 200 and polished on a staticpolishing member. FIG. 20 is a schematic illustration of polishing speedvectors of different parts of polishing fixture 200. The use of a staticpolishing member together with the sliding movement mechanism underdigital control ensures that all of the connectors move along the samepolishing path simultaneously and at the same speed. The capability ofpositioning polishing fixture 200 on practically any area of polishingmember 286 enabled by X-Y stages movement and digital orbital controlallows better polishing paper utilization and an overall increase inmachine throughput.

While the exemplary embodiments of the present invention have beenillustrated and described, it will be appreciated that various changescan be made therein without affecting the spirit and scope of theinvention.

1. A polishing system for polishing optical connectors, the polishingsystem comprising: (a) at least one polishing station including a regionof polishing film overlying a substrate block; (b) a polishing fixturehaving: (i) a plurality of connector mounting holes disposed across anarea of said polishing fixture, each of said connector mounting holesreceiving an optical connector, and (ii) a working liquid supplyarrangement including a plurality of working liquid release channels fordirecting working liquid to regions adjacent to said connector mountingholes, at least one of said working liquid release channels beinginterspaced between a plurality of said connector mounting holes; and(c) a drive system for generating relative motion between said polishingfixture and said at least one polishing station so as to polish theoptical connectors.
 2. The polishing system of claim 1, wherein each ofsaid connector mounting holes has a nearest neighbor spacing measuredfrom said connector mounting hole to a nearest neighboring connectormounting hole, and wherein a spacing from each of a majority of saidconnector mounting holes to a nearest one of said working liquid supplychannels is not more than twice an average of said nearest neighborspacings.
 3. The polishing system of claim 1, wherein a majority of saidconnector mounting holes are substantially equidistant from a nearestone of said working liquid supply channels.
 4. The polishing system ofclaim 1, wherein said polishing fixture includes a mounting plate, bothsaid connector mounting holes and said working liquid supply channelsbeing formed as openings through said mounting plate.
 5. The polishingsystem of claim 1, wherein said drive system is associated with saidpolishing fixture so as to move said polishing fixture along atwo-dimensional polishing path relative to said at least one polishingstation and wherein said at least one polishing station is configured tohold said region of polishing film static while said polishing fixturemoves along said polishing path.
 6. The polishing system of claim 5,wherein said drive system is further configured to raise said polishingfixture out of contact with said at least one polishing station oncompletion of a polishing operation.
 7. The polishing system of claim 6,wherein said drive system is implemented as a set of three linearactuators.
 8. The polishing system of claim 1, further comprising anoptical cable support including at least one reel for receiving lengthsof optical cables associated with the optical connectors being polished.9. The polishing system of claim 8, wherein said cable support furtherincludes a displacement mechanism configured to allow displacement ofsaid reel in at least one direction.
 10. The polishing system of claim1, further comprising a flexible optical circuit support rack associatedwith said polishing fixture for supporting a flexible optical circuitassociated with the optical connectors being polished.
 11. The polishingsystem of claim 10, wherein said flexible optical circuit support rackincludes a clamping plate extending vertically above said polishingfixture, said clamping plate having a two dimensional array of boltholes.
 12. The polishing system of claim 1, further comprising acleaning station including: (a) a wiping cloth supply roll; (b) a wipingcloth receiving roll; (c) a length of wiping cloth partially stored onsaid supply roll and stretched to said receiving roll to as to leave anexposed wiping cloth region; and (d) a winding actuator associated withsaid receiving roll and configured for actuating said receiving roll soas to bring a new portion of said length of wiping cloth into saidexposed wiping cloth region.
 13. The polishing system of claim 12,wherein said supply roll, said receiving roll and said length of wipingcloth are implemented as parts of a wiping cloth cassette.
 14. Thepolishing system of claim 1, further comprising: (a) a polishing filmfeed mechanism for selectively exchanging said region of polishing filmoverlying said substrate block; and (b) a computerized controller forcontrolling said drive system and said feed mechanism, said controllerbeing configured to: (i) actuate said drive system during a firstpolishing operation so as to move a batch of optical connectors in apolishing motion along a corresponding set of polishing profiles incontact with the static polishing film, (ii) actuate said drive systemduring at least one additional polishing operation so as to move a batchof optical connectors in a polishing motion along a corresponding set ofpolishing profiles in contact with the static polishing film, saidpolishing profiles of said additional polishing operation beinginterspaced with, and non-overlapping, said polishing profiles of saidfirst polishing operation, and (iii) actuate said feed mechanism so asto advance said polishing film.
 15. A polishing system for polishingoptical connectors, the polishing system comprising: (a) at least onepolishing station including a region of polishing film overlying asubstrate block; (b) a polishing film feed mechanism for selectivelyexchanging said region of polishing film overlying said substrate block;(c) a polishing fixture having a plurality of connector mounting holesdisposed across an area of said polishing fixture, each of saidconnector mounting holes receiving an optical connector; (d) a drivesystem for generating relative motion between said polishing fixture andsaid at least one polishing station so as to polish the opticalconnectors; and (e) a computerized controller for controlling said drivesystem and said feed mechanism, said controller being configured to: (i)actuate said drive system during a first polishing operation so as tomove a batch of optical connectors in a polishing motion along acorresponding set of polishing profiles in contact with the staticpolishing film, (ii) actuate said drive system during at least oneadditional polishing operation so as to move a batch of opticalconnectors in a polishing motion along a corresponding set of polishingprofiles in contact with the static polishing film, said polishingprofiles of said additional polishing operation being interspaced with,and non-overlapping, said polishing profiles of said first polishingoperation, and (iii) actuate said feed mechanism so as to advance saidpolishing film.
 16. A polishing system for polishing optical connectors,the polishing system comprising a cleaning station having: (a) wipingcloth cassette including: (i) a wiping cloth supply roll, (ii) a wipingcloth receiving roll, and (iii) a length of wiping cloth partiallystored on said supply roll and stretched to said receiving roll to as toleave an exposed wiping cloth region; and (b) a winding actuatorassociated with said receiving roll and configured for actuating saidreceiving roll so as to bring a new portion of said length of wipingcloth into said exposed wiping cloth region.
 17. A method for polishingoptical connectors of a flexible optical circuit, the method comprising:(a) providing a polishing fixture including: (i) a plurality ofconnector mounting holes disposed across an area of said polishingfixture, each of said connector mounting holes receiving an opticalconnector, and (ii) a support rack for supporting a flexible opticalcircuit; (b) mounting a flexible optical circuit with a plurality ofoptical connectors mounted in the connector mounting holes and with atleast part of a body of the flexible optical circuit attached to thesupport rack; and (c) generating relative motion between the polishingfixture and a polishing surface.
 18. The method of claim 17, whereinsaid relative motion is generated by a drive system associated with thepolishing system, the polishing surface remaining static at least duringa given polishing operation.
 19. A method of polishing of the leadingend face portion of a plurality of batches of optical connectors havinga foremost end having a ferrule integrated with optical fiber,comprising steps of: (a) mounting first batch of optical connectors in apolishing fixture having a plurality of optical connectors mountingholes at a predetermined inclination angle and a plurality of workingliquid delivery openings interspaced with said optical connectorsmounting holes; (b) bringing said leading end faces of said mounted inthe polishing fixture first batch optical connectors into forced contactwith a static polishing member; (c) sliding said polishing fixture withthe first batch of optical connectors simultaneously in two independentand orthogonal directions on said polishing member; (d) supplyingthrough a plurality of openings and channels in said polishing fixture aworking liquid to a plurality of optical connectors being polished andto said polishing member; (e) polishing the surface of the leading endface portion of the first batch of optical connectors by said slidingmovement in a brushing pattern generated by independent changes of saidsliding movement speed in each of said two orthogonal polishing fixturemovement directions; and (f) controlling all of the polishing andauxiliary processes by a computer, said computer monitoring andmemorizing all of the processes steps and parameters, wherein at leastone of the polishing process parameters for polishing the surface of theleading end face portion of at least one of the following opticalconnector batches is changed by said computer, based on the results ofpreviously polished optical connectors batch.